Heroic officers Acting Police Sergeant Stephen Rabjohns for Heston Central, and Hounslow Police Sergeant Allan Shields, were part of the overnight emergency response team on duty on June 14 2015.

They spoke about the frenzied attack on a man who was left to die after being stabbed 27 times, including four times in the heart, and how they assisted with his open heart surgery on the roadside.

The officers responded to an initial call to reports of a fight with baseball bats and multiple weapons on Staines Road, Bedfont, and were heading over when an update came through that the suspects had fled the scene and there was a casualty with life threatening injuries, which became priority.

On arriving at the crime scene, Sgt Rabjohns, who is a qualified medic, said: “There were four officers already trying to administer first aid.

“I asked them to reposition the casualty to allow us and the ambulance service access to the man. We had to remain cautious as one of the weapons was still there.

“Officers at the scene had stripped him, which allowed us to see the extent of his injuries.”

It was very quickly clear to them they would have to use duct tape to keep blood from gushing out and his lungs inflated.

'People don't realise the speed at which this has to be done'

For 45 minutes they battled to save the 29-year-old's life, joined by paramedics from the ambulance service, HEMS doctors, and colleagues.

A rescue mask was put on the victim, and the Sgt Rabjohns and Shields began to patch him up starting with the most serious wounds, while at the same time monitoring his breathing.

They discovered a potentially deadly stab wound under the left armpit which can puncture the lungs and heart, and were further horrified when they turned the victim on his side to find a 10cm gash on his back.

“We turned him onto his left side and found an incredibly large wound to the back where we could see his internal organs spilling out,” said Sgt Shields.

“The wound was so significant the duct tape was not enough to cover it. I shouted at Steve to hold the organs in place and used the biggest sticky dressing to cover it. We had to push everything back in and tape him up.

“You look at how much blood on the floor, how much was on him and on us – his blood count must have been fatally low.

“What people don't realise is the speed at which this has to be done.”

Crime investigation begins

While lifesaving work was taking place inside the supermarket, outside acting inspector for Feltham , Chris Mulrooney, and a team of officers launched an investigation.

A crime scene was set up, a sterile safe area for surgery, road blocked off, and witness statements were taken.

Once the ambulance service and HEMS arrived Sgt Rabjohns brought them up to speed. The victim was moved on a stretcher outside for open heart surgery, where other officers joined to help including PCs Darren Greenall and Anthony Elsemere holding torch lights, lamps and squeezing a bag of blood while the HEMS doctors performed the surgery.

Sgt Shields added: “This couldn't have happened unless this whole other team was with us as well.

“There were flats overlooking the crime scene and to give some dignity to the victim who was naked, and shield the public from what was happening as some people may have an adverse reaction to it, we surrounded the area.

“The medics were sewing up his internal organs while another team of people were keeping everyone at bay.

“They had to pull his ribcage apart then force blood in and sew up holes in his heart. The HEMS doctor was incredible.

“We assisted the medics until he was taken to Paddington – St Mary's Hospital.